In the process of storage, transportation, and sales, "cold chain" operation is a necessary condition to ensure the quality of quick-frozen food. "Quick-frozen pre-packaged rice food hygiene standards" stipulate that in the storage, transportation and sales of quick-frozen food, the temperature should be controlled below -18℃, and the temperature fluctuation should not exceed 2℃. Reaching this standard can effectively reduce the loss of water in the food, inhibit the reproduction of microorganisms, reduce the activity of various biological enzymes in the food, and maintain the nutritional content and original flavor of the food to the maximum extent. From the storage facilities of the manufacturer to the refrigerated trucks that transport food, the freezers in the sales link, and the refrigerators in the consumers' homes, all should meet this condition. However, a considerable part of supermarkets' quick-frozen foods are operated in open cabinets, and the freezer has no temperature display, so it is difficult to reach the required temperature. When the food is not sold out, it is not stored in the cold storage, but is kept in the open refrigerator. If the temperature is higher than -10℃, the shelf life of quick-frozen food will be greatly shortened, and it may deteriorate after a few days. In the transportation process, some companies do not use special refrigerated trucks, and some hand-crafted workshops even wrap the food with quilts, which causes some foods to thaw and stick during transportation, which affects the appearance and reduces the product quality.